Table roll mounting



Jan. 28, 1969 0. s DE NOYER ET 3,424,651

TABLE ROLL- mouu'rme Filed Oct. 22. 1965 Sheet 2 %d7 &'W/WATTORNEYS zUnited States Patent 9 Claims ABSTRACT UP THE DISCLGSURE A table rollassembly for a Fourdrinier wire having an outer cylindrical roll shellfor supporting a load along its axial length, an inner solid shellsupporting shaft means extending through the shell adapted to benon-rotatably mounted at its ends, end bearing means between the shaftand the roll shell for rotatably supporting the ends of the roll shell,and intermediate rotatable bearings mounted between the end bearings andpositioned between the shaft and the intermediate surface of the rollshell with the end bearing and the intermediate rotatable bearings beingeccentric relative to each other an amount which supports the roll shellso that its outer surface remains substantially axially straight and theinternal shaft bends due to the forces on the roll shell.

The present invention relates to improvements in roll assemblies andmore particularly to an improved table ro l for a paper machine with asupport which is capable of holding the roll substantially axiallystraight for a given condition.

While the features of this invention may be embodied in other rollswhich sustain loads during use, the invention is particularlyadvantageous and well-adapted for use in paper making machines andespecially for a table roll which provides a dewatering support beneatha Fourdrinier wire. In the manufacture of making paper the watersuspension of pulp is deposited on a traveling Fourdrinier wire and thepulp is dewatered to form a web with the web subsequently being removedfrom the wire to be pressed and further dried. It is important to thesatisfactory operation of the machine and to the formation of a goodpaper web that the table roll beneath the wire be maintainedsubstantially straight to provide a horizontal planar support for thewire.

In the initial stages of dewatering, the table rolls are frequently usedwhich extend across the machine beneath the Fourdrinier wire and have aneffect well known to those versed in the art which draws water from theweb through the wire on the off-running side of the roll. The weight ofthe wire and the web with water tend to cause a sag of the table roll ina vertical direction. Also, the forces caused by the reaction betweenthe roll surface and the wire, including the frictional force of thewire driving the roll, the pressure differential between the uppersurface of the web in the zone of the off-running side of the table rol, and the water striking the roll cause deflection of the roll in themachine direction, or in other words, in the direction of wire travel.This is particularly true near the breast roll where a large volume ofwater is removed. These rolls have a tendency to sag in any length andthe trend in paper machine manufacture has been to increasingly greaterwidths so that paper machines having widths of 30 feet or more have nowbeen manufactured. While the diameter of the table roll can be increasedto increase its beam strength, this is not always desirable since thereare optimum diameters of table rolls for predetermined machine speedswhich give the maximum advantages in water removal. That is, thediameter of the table roll should be chosen so that substantial maximumwater removal is achieved and an optimum relationship between the weband table roll is obtained without concern as to the beam strength ofthe table roll across the machine.

Deflection must be minimized but cannot be avoided. It is desirable thatthe deflection of the table roll match other components such as thebreast roll, forming board, deflectors, etc. It is also desired that thedeflection can be changed or controlled so as to match other components.

With the trend to greater widths (30 feet or more) and the increase inmachine speeds, the diameter of the roll needs to be increased tominimize deflection and to provide a roll which will not whip at highspeed. These large rolls are not the optimum for formation and it is anobject of the invention to reduce the diameter, control the deflectionto a minimum and to provide a roll of small diameter which will not whipat high speed.

A further object of the invention is to provide a substantially axiallystraight table roll assembly which utilizes a solid supporting shaftextending through the center of the table roll and avoids thedisadvantages used in arrangements heretofore available.

A stil further object of the invention is to provide an improved tableroll assembly which eliminates or decreases deflection caused by theweight of the roll assembly and by external loads such as wire sag load,water load, and other forces, wherein wire wear usually caused byincreased tension on the edges due to wire sag is avoided, and whereindisadvantageous drainage and resultant improper web formation areavoided.

More particularly, the invention embodies a supporting roll assemblyhaving a substantially cylindrical outer surface for supporting a loadalong its axial length, such as the type used for a table roll in aFourdrinier machine, including a roll shell for positioning across apaper machine beneath a Fourdrinier wire, a horizontal solid internalshell supporting shaft extending through the roll shell and adapted tobe nonrotatably mounted at its ends, end bearings between the shaft andthe roll shell for rotatably supporting the ends of the roll shell, andintermediate bearings positioned between the end bearings and locatedbetween the shaft and the internal surface of the roll shell with theend bearings and intermediate bearings being eccentric relative to eachother an amount which supports the roll shell with its outer surfacesubstantially axially straight as the internal shaft bends due to forceson the roll shell.

Other objects, advantages and features of the invention will become moreapparent with the teaching of the principles of the invention inconnection with the disclosure of the preferred embodiment thereof inthe specification, claims, and drawings in which:

FIGURE 1 is a schematic showing of a section taken through a roll shellassembly embodying the principles of the present invention;

FIGURE 2 is a fragmentary schematic showing of a portion of aFourdrinier section of a paper machine illustrating the location oftable rolls;

FIGURES 3 and 4 are schematic showings of bearing arrangements inaccordance with the principles of the invention;

FIGURE 5 is a more detailed vertical sectional view taken through a rollshell assembly showing certain structural details of an operablestructure embodying the invention; and

FIGURE 6 is a vertical sectional view taken substantially along the lineVIVI of FIGURE 5.

As illustrated in FIGURE 1, the table roll assembly shown includes anouter roll shell 10 which is of a length so that it is slightly longerthan the width of a Fourdrinier wire to be supported on the roll shell.The shell has a smooth cylindrical outer surface and is of a diameterwhich provides optimum dewatering without disadvantageous effects to theweb being formed and dewatered on the wire.

Support for the roll shell is afforded by a solid central shaft means 11which extends through the roll shell and is adapted to be supported atits ends by supports 12 and 13. The Fourdrinier assembly has suitablemembers on the framework for supporting the shaft 11 in a nonrotatablemanner.

Rotatably supporting the roll shell 10 on the nonrotat-able shaft 11 areend bearings 14 and 15, and an intermediate bearing 16 therebetween. Theintermediate bearing 16 is eccentric relative to the end bearings 14 andan amount so that as the shaft 11 bends during operation due to the loadon the roll shell the roll shell will be held substantially axiallystraight. That is, a straight support will be provided holding theFourdrinier wire horizontal.

FIGURE 2 illustrates a typical Fourdrinier section with a. travelingFourdrinier wire 19 being supported horizontally so that a pulpsuspension is discharged onto it from a headbox 20. The wire issupported by breast roll 21 and a couch roll, not shown, and the pulpsuspension on the wire forms a Web W and passes over the dewateringmechanism such as a series of table rolls 22 and a suction box 23. Theformed web is taken off of the wire following the couch roll and passedthrough presses and a subse quent drier section and is wound on a roll.

The eccentricity of the bearings may be arranged in different ways eachdesigned to obtain a substantially straight roll shell when thestructure is operating under load. As illustrated in FIGURE 3, the axisor centerline of the roll shell is shown at 24 with the axis orcenterline of the non-rotatable solid shaft at 25. End supports 26 and27 are provided. In the arrangement of FIGURE 3, the end bearings 28 and29 are non-eccentric relative to the axis of the shaft and intermediatebearing 30 is eccentric. The deflection of the axis of the shaft isemphasized with the line at 30 showing the eccentricity of theintermediate hearing.

In the arrangement of FIGURE 4, the axis of the roll shell is shown at24 and the axis of the solid non-rotatable shaft is shown at In thisarrangement, an intermediate bearing is provided which is concentricwith the shaft and end bearings 28 and 29 are eccentric by an amount sothat with deflection of the shaft due to load, the roll shell willremain substantially straight. The end supports 26' and 27 for the shaftin FIGURE 4 and the end supports 26 and 27 for the shaft in FIGURE 3 arevertically adjustable so that the roll shell can be brought up and truedto the proper height and level relative to the rest of the wire.

While in the invention is shown the preferred structure as having twoend bearings and one intermediate bearing, it will be appreciated thatmore intermediate bearings can be used and the eccentricity of each willdepend upon their location. For example, in the arrangement of FIG- URE3, if additional intermediate bearings are provided between intermediatebearing 30 and the end bearing 29 their eccentricity will be thedistance between the axis of the shaft and the axis of the roll shell.This eccentricity is determined by the deflection of the roll due to itsown weight and also external load considerations. These loadconsiderations are a function of the speed of the machine, the type ofpaper being formed, consistency of the pulp, and other factors. It iscontemplated that the bearings will either be replaceable with bearingsof other eccentricities or will be adjustable so that under differentenvironments, different eccentricities may be obtained to obtain asubstantially straight roll shell. The conditions of FIGURES 3 and 4 areunder load and it will be appreciated that under no load conditions, theaxis of the roll shell will assume some position different than thatshown in the drawings at which the actual deflection forces of the rollshell and shaft are at equilibrium. The structures are designed,however, with the shaft in its natural unloaded condition independentfrom the roll shell being straight. The roll shell is also constructedso that its natural unloaded condition is straight.

FIGURE 5 shows an operating assemblage with the roll shell 31 providedwith an outer covering 32 thereon. Extending through the roll shell is acentral shaft 33. While the shaft illustrated is shown hollow forconvenience because of its size, in accordance with the principles ofthe present invention, it is unnecessary to provide a hollow shaft andthe central shaft can be solid. In other words, the central shaft doesnot have to be hollow to provide passageways for supports or mechanismfor controlling the shape or deflection of the central shaft so that itneed only be of a size adequate so that it will not have excessivedeflection with load to cause permanent distortion. The outer diameterof the roll shell is chosen to conform with the dictates of optimumperformance relative to dewatering the web on the wire.

The shaft 33 is carried on end supports 34 and 35 on the machine.Inasmuch as each end support is the same, only the structural details ofend support 35 need be provided and the end supports have a jacking bolt36 for moving them up or down to true them relative to the wireposition. The shaft is carried in a self-aligning support 37 permittingunrestricted deflection of the shaft 33. End plate 38 supports alubrication line 39 leading to the intermediate or central bearing 42.

The roll shell is supported on the shaft 33 by the intermediate bearing42 and end bearings 40 and 41. In the arrangement illustrated, thecentral bearing is concentric with the shaft and the end bearings areeccentric. Suitable lubrication passages 42 and 43 are provided for theend bearings 40 and 41.

As illustrated in FIGURE 6, the end bearing 41 is adjustable as to thelocation of eccentricity with an index line 44 indicating the locationof maximum eccentricity. It will be noted that the bearing is set sothat the center line 46 of the roll shell 31 is offset both verticallyand horizontally from the centerline 45 of the shaft 33. Theeccentricity of the axis 46 of the roll shell forms an angle A relativeto the axis 45 of the shaft 33. The vertical eccentricity is shown as adistance C and the horizontal eccentricity is shown as a distance B. Inother words, due to the vertical load and machine direction load on theroll shell, the shaft will deflect an amount vertically equal to thedistance C. The eccentricities on the shaft are adjusted so that thedistance B is the same at the center and ends which permits the bearingcenters to lie on a horizontal straight line in a vertical plane whenthe desired vertical deflection C takes place.

As shown in FIGURE 5, the shaft 33 has radially offset or eccentric ends33a. These ends support eccentric bushings 40a which carry the endbearings 40 and which are shaped so that the end bearings 40 areeccentric relative to the intermediate bearing 42. The direction ofeccentricity (the relative positions of the centers of the relativelyeccentric end bearings 40 and intermediate bearing 42) is adjustable, asdescribed above in connection with FIGURE 6 by either rotating theentire shaft 33 or rotating the eccentric end bushings 40a relative tothe shaft 33.

In summary, end bearings and intermediate bearings are chosen to supportthe roll shell 31 on the central shaft 33 and are eccentric relative toeach other. Either the intermediate bearing or the end hearings (or acombination of both) may be chosen to be eccentric relative to the shaftand the eccentricity is predetermined to be an amount which will permitfree deflection of the shaft due to the load on the roll shell andmaintain the roll shell axially straight.

Thus it will be seen that we have provided an improved roll assemblywhich meets the objectives and advantages above set forth. The structureobtains advantages over devices heretofore available in the prior artand permits obtaining a table roll of optimum size without resorting toprebo'wing the shaft or introducing a counter couple to straighten theshaft and roll body. The structure can be constructed in a relativelyinexpensive and simple manner and permits operation without frequentadjustment and servicing or repair.

The drawings and specification present a detailed disclosure of thepreferred embodiments of the invention, and it is to be understood thatthe invention is not limited to the specific forms disclosed, but coversall modifications, changes and alternative constructions and methodsfalling within the scope of the principles taught by the invention.

We claim as our invention:

1. A table roll for providing a de-watering support for a Fourdrinierwire comprising, a roll shell positioned across a paper machine beneatha Fourdrinier wire, a shell support shaft means extending through saidroll shell and adapted to be non-rotatably mounted, end bearing meansbetween the shaft means and the roll shell rotatably supporting the rollshell, and intermediate rotatable bearing means between the shaft meansand the internal surface of the roll shell and located between the endbearing means for rotatably supporting the roll shell, said intermediaterotatable bearing means being eccentric with respect to said end bearingmeans for supporting the shaft means with the roll shell having asubstantially straight axis and the shaft means bending due to the forceon the roll shell.

2. A table roll for providing a de-watering support for a FourdrinierWire comprising, a roll shell positioned beneath a Fourdrinier wire, ahorizontal shell supporting shaft means extending through said rollshell and adapted to be non-rotatably mounted, end bearing means betweenthe shaft means and the roll shell rotatably supporting the roll shell,and intermediate rotatable bearing means between the shaft means and theinternal surface of the roll shell and between the end bearing means forrotatably supporting the roll shell, said intermediate rotatable bearingmeans being vertically eccentric with respect to said end bearing meansfor supporting the shaft means with the roll shell having asubstantially straight axis and the shaft means bending due to forces onthe roll shell.

3. A supporting roll assembly having a substantially cylindrical outersurface for supporting a load along its axial length such as a travelingweb comprising, a roll shell having an outer substantially cylindricalsupporting surface, a horizontal shell-supporting shaft means extendingthrough said roll shell and adapted to be non-rotatably mounted, endbearing means between the shaft means and the roll shell for rotatablysupporting the roll shell, and intermediate rotatable bearing meansbetween the shaft means and the internal surface of the roll shell andbetween said end bearing means for rotatably supporting the roll shell,said intermediate rotatable bearing means being eccentric with respectto said end bearing means for supporting the roll shell substantiallyaxially straight as the shaft means bends with the forces on the rollshell.

4. A supporting roll assembly as defined in claim 3 'wherein the axialcenter of said end bearing means and said intermediate rotatable bearingmeans are relatively rotationally adjustable so that verticaleccentricity can be changed.

5. A table roll for providing a de-Watering support for a Fourdrinierwire comprising a roll shell positioned beneath a Fourdrinier wire, ashell supporting shaft means extending through said roll shell andadapted to be nonrotatably mounted, said shaft means being axiallystraight when free of load, end bearing means between the shaft meansand the roll shell rotatably supporting the roll shell, and intermediaterotatable bearing means between the shaft means and the internal surfaceof the roll shell and between the end bearing means for rotatablysupporting the roll shell, said intermediate rotatable bearing meansbeing eccentric with respect to said end bearing means for supportingthe shaft means with the roll shell having a substantially straight-axisand the shaft means bending due to force on the roll shell.

'6. A table roll for providing a de-watering support for a Fourdrinierwire comprising, a roll shell positioned beneath a Fourdrinier wire, ashell supporting shaft means extending through said roll shell andadapted to be non-rotatably mounted, en d bearing means between theshaft means and the roll shell rotatably supporting the roll shell, andintermediate rotatable bearing means between the shaft means and theinternal surface of the roll shell and between the end bearing means forrotatably supporting the roll shell, said intermediate rotatable hearingmeans and said end means being eccentric relative to each other inamounts that the shaft means bows with loads and the roll shell is heldsubstantially straight in an axial direction.

7. A table roll for providing a de-watering support for a Fourdrinierwire comprising, a roll shell positioned beneath a Fourdrinier wire, ashell-supporting shaft means extending through said roll shell andadapted to be nonrotatably mounted, end bearing means between the shaftmeans and the roll shell rotatably supporting the roll shell, andintermediate rotatable bearing means between the shaft means and theinternal surface of the roll shell and between the end bearing means forrotatably supporting the roll shell, said end bearing means beingconcentric with the shaft and said intermediate rotatable bearing meansbeing eccentric relative to the shaft axis so that the shaft bends withthe load and the roll shell remains substantially axially straight.

8. A table roll for providing a de-watering support for a Fourdrinierwire comprising, a roll shell positioned across a paper machine beneatha Fourdrinier wire, a shell-supporting shaft means extending throughsaid roll shell and adapted to be non-rotatably mounted, end bearingmeans between the shaft means and the internal surface of the rod shelland between the end bearing means for rotatably supporting the rollshell, and intermediate rotatable bearing means between the shaft meansand the internal surface of the roll shell and between the end bearingmeans for rotatably supporting the roll shell, said intermediaterotatable bearing means being concentric with respect to said shaft andsaid end bearing means being eccentric relative to the shaft axis sothat the shaft means bends with the load and the roll shell remainssubstantially axially straight.

9. A table roll for providing a de-watering support for a Fourdrinierwire, comprising, a roll shell positioned beneath the Fourdrinier wire,a shell-supporting shaft means extending through said roll shell andadapted to be non-rotatably mounte'd, rotary end bearing means mountedbeneath said shaft means and said roll shell rotatably supporting saidroll shell, and rotary intermediate bearing means mounted betweenbetween said shaft means and the internal surface of said roll shell andbetween said rotary end bearing means for rotatably supporting said rollshell, said rotary intermediate bearing means being eccentric withrespect to said end rotary bearing means for supporting said shaft meanswith said roll shell having a substantially straight axis and the 7 8shaft means bending due to force on said roll shell, said ReferencesCited shaft means being substantially axially straight when free UNITEDSTATES PATENTS of load, said shaft means and roll shell havingnon-parallel axes, said rotary bearings between said shaft means and1868860 7/1932 Von 1'' 19337 roll shell being non-concentric relative toeach other a 5 DONALL SYLVESTER Pr'mary Examme" pre-determined amount sothat With a load on said roll HODGSON, Assistant Examinershell saidshaft means will bend while said roll shell re- U.S. Cl. X.R. mainssubstantially axially straight. 29-113; 162 372; 193 37

